JP2010154011A - Isolator and method of transmitting signals - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To solve the problem wherein reliability of a photocoupler declines because a light emitting element or a light receiving element is degraded. <P>SOLUTION: This isolator 100 includes a primary region 10 and a secondary region 30 electrically insulated from each other, and signals are transmitted from the primary region 10 to the secondary region 30. A coil 14 is provided in the primary region 10. A current generation part 12 supplies a driving current Idrv corresponding to the signals Sin to be transmitted to the coil 14. A hall element 32 is provided close to the coil 14 in the primary region 10 and receives a magnetic flux generated by the coil 14. An amplifier 34 amplifies hall signals H+ and H- generated in the hall element 32 according to the magnetic flux. <P>COPYRIGHT: (C)2010,JPO&amp;INPIT

Description

  The present invention relates to an isolator that transmits and receives signals in two electrically isolated regions.

  Isolators are used to transmit information between two regions that are to be electrically isolated from each other. For example, as a typical isolator, a photocoupler using light as an information transmission medium is known.

The photocoupler is provided in a primary region (transmission side) and a secondary region (reception side) that are electrically isolated from each other, and a light emitting device (for example, a light emitting diode) provided in the primary region, and in the secondary region. A light receiving device (for example, a photodiode).
JP-T-2001-521160

  However, the photocoupler has a problem of a decrease in reliability due to deterioration of the light emitting element or the light receiving element.

  The present invention has been made in view of such problems, and one of its purposes is to provide a highly reliable isolator.

  An aspect of the present invention relates to an isolator that includes a primary region and a secondary region that are electrically insulated from each other and transmits a signal from the primary region to the secondary region. The isolator is provided in the vicinity of the coil provided in the primary region, the current generator that supplies the drive current corresponding to the signal to be transmitted to the coil, and the coil in the primary region, and generates the magnetic flux generated by the coil. A Hall element that receives the signal, and an amplifier that amplifies an electric signal generated in the Hall element according to the magnetic flux.

  According to this aspect, by utilizing the Hall element, the primary region and the secondary region can be suitably coupled using a magnetic field. Since the coil and the Hall element are less deteriorated than the light emitting element and the light receiving element, a highly reliable isolator is provided. In addition, Hall elements and coils are highly compatible with semiconductor processes and can be integrated with other circuits such as current generators and amplifiers on a semiconductor substrate such as silicon, making the isolator compact. There is an advantage that you can.

  Note that any combination of the above-described constituent elements and the constituent elements and expressions of the present invention replaced with each other among methods, apparatuses, systems, and the like are also effective as an aspect of the present invention.

  According to an aspect of the present invention, a highly reliable isolator can be provided.

  The present invention will be described below based on preferred embodiments with reference to the drawings. The same or equivalent components, members, and processes shown in the drawings are denoted by the same reference numerals, and repeated descriptions are omitted as appropriate. The embodiments do not limit the invention but are exemplifications, and all features and combinations thereof described in the embodiments are not necessarily essential to the invention.

In this specification, “the state in which the member A is connected to the member B” means that the member A and the member B are electrically connected in addition to the case where the member A and the member B are physically directly connected. It includes the case of being indirectly connected through another member that does not affect the connection state.
Similarly, “the state in which the member C is provided between the member A and the member B” refers to the case where the member A and the member C or the member B and the member C are directly connected, as well as an electrical condition. It includes the case of being indirectly connected through another member that does not affect the connection state.

  FIG. 1 is a circuit diagram showing a configuration of an isolator 100 according to an embodiment of the present invention. The isolator 100 is divided into a primary region 10 and a secondary region 30 that are electrically insulated from each other, and an input signal Sin input to the input terminal 16 on the primary region 10 side is input to the secondary region 30 side. The output signal Sout is output from the output terminal 36 according to the input signal Sin.

  The primary region 10 and the secondary region 30 are desirably formed on different semiconductor substrates. This is because noise and signals are prevented from leaking between the two regions through the semiconductor substrate and isolation is increased. Furthermore, a power supply terminal and a ground terminal are provided independently on the primary region 10 side and the secondary region 30 side, respectively. Specifically, the first ground terminal 18 and the first power supply terminal 20 are provided on the primary region 10 side, and the second ground terminal 38 and the second power supply terminal 40 are provided on the secondary region 30 side. .

  The isolator 100 includes a current generator 12, a coil 14, a Hall element 32, and an amplifier 34.

The primary region 10 will be described.
The coil 14 is provided in the primary region 10. The coil 14 may be a chip component, but is preferably integrated on one semiconductor substrate together with other circuit elements (current generation unit 12) on the primary region 10 side. One end of the coil 14 is connected to the first ground terminal 18. The current generator 12 is connected to the other end of the coil 14 and supplies a drive current Idrv corresponding to the input signal Sin to be transmitted to the coil 14. For example, the current generator 12 may be a voltage-current converter circuit such as a gm amplifier. The current generator 12 operates by receiving the power supply voltage Vdd1 supplied to the first power supply terminal 20.

  A magnetic flux corresponding to the drive current Idrv is generated in the coil 14, and the strength of the magnetic flux changes according to the input signal Sin.

  Next, the secondary region 30 will be described. The Hall element 32 is provided close to the coil 14 in the primary region 10 so as to receive the magnetic flux generated by the coil 14. Hall element 32 receives reference bias voltages Vref + and Vref−. The secondary region 30 may be provided with a bias circuit (not shown) that generates the reference bias voltages Vref + and Vref−. The Hall element 32 is integrated on a single semiconductor substrate together with other circuit elements (34) provided in the secondary region 30. Alternatively, the Hall element 32 may be formed on a semiconductor substrate different from the amplifier 34, or a chip component may be used.

  An electrical signal (Hall signals H +, H−) is generated in the Hall element 32 in accordance with the magnetic flux from the coil 14. The amplifier 34 amplifies the Hall signals H + and H− generated by the Hall element 32. The signal amplified by the amplifier 34 is directly output from the output terminal 36 as the output signal Sout. Alternatively, a signal processing circuit (not shown) may be provided at the subsequent stage of the amplifier 34, and a predetermined signal processing may be performed on the output signal of the amplifier 34 and then output from the output terminal 36.

  The above is the configuration of the isolator 100. According to isolator 100 according to the embodiment, a signal can be transmitted between two electrically insulated regions by a pair of a coil and a Hall element. The coil and the Hall element are less deteriorated with time and have less variation in characteristics than the LEDs and photodiodes used in conventional isolators (photocouplers), so that the long-term reliability of the isolator 100 is improved. be able to.

  Although the present invention has been described using specific words and phrases based on the embodiments, the embodiments are merely illustrative of the principles and applications of the present invention, and the embodiments are defined in the claims. Many modifications and arrangements can be made without departing from the spirit of the present invention.

It is a circuit diagram which shows the structure of the isolator which concerns on embodiment of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 100 ... Isolator, 10 ... Primary region, 12 ... Current generating part, 14 ... Coil, 16 ... Input terminal, 18 ... First ground terminal, 20 ... First power supply terminal, 30 ... Secondary region, 32 ... Hall element, 34... Amplifier, 36... Output terminal, 38... Second ground terminal, 40.

Claims (2)

An isolator that includes a primary region and a secondary region that are electrically isolated from each other and transmits a signal from the primary region to the secondary region;
A coil provided in the primary region;
A current generator that supplies a drive current corresponding to the signal to be transmitted to the coil;
A Hall element provided close to the coil in the primary region and receiving a magnetic flux generated by the coil;
An amplifier that amplifies an electrical signal generated in the Hall element in response to the magnetic flux;
An isolator comprising: A method of transmitting a signal between a primary region and a secondary region that are electrically isolated from each other,
Supplying a drive current corresponding to a signal to be transmitted to a coil provided in the primary region, and generating a magnetic flux in the coil;
Generating an electrical signal corresponding to the magnetic flux in a Hall element provided in a location that receives the magnetic flux generated by the coil in the secondary region;
Extracting the electrical signal as a signal corresponding to the signal to be transmitted;
A method comprising the steps of:

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